Air-conditioned item of footwear with device for extraction of the condensate

ABSTRACT

The present invention concerns an air-conditioned item of footwear ( 1 ), suitable for causing condensation of the humidity that is formed inside as a result of the perspiration of the foot, as well as to collect and extract the condensate. This air-conditioned item of footwear ( 1 ) it&#39;s of the type that envisages first means, operated by the foot, designed to generate a circulation of air in a gap ( 6 ) made in the upper ( 5 ) of said item of footwear, said air being taken in from outside said item of footwear ( 1 ), said item of footwear being characterized in that it envisages second means designed to expel outside said item of footwear the water deriving from condensation of the water vapour emitted by the foot, said condensation occurring within said gap ( 6 ) of said upper ( 5 ) as a result of cooling actuated by said air.

The present invention concerns an air-conditioned item of footwear, suitable for causing condensation of the humidity that is formed inside as a result of the perspiration of the foot, as well as to collect and extract the condensate. In other words, the item of footwear according to the invention is provided with a first device that, by ventilating the inside of the upper, cools it and causes condensation of the humidity produced by the foot, and a second device that collects the condensate and expels it outside the item of footwear. It is common experience that, in the event of insufficient transpiration, the perspiration of the foot can even dampen completely the socks causing suffering of the foot itself, in particular of the skin. This fact arises in a particularly drastic way in the case where waterproof items of footwear are worn for many hours a day, especially if they are high, such as wellingtons. In particular, this problem is felt by many workers, in different working sectors, where they are forced to wear waterproof items of footwear for at least eight hours a day.

There exist numerous patents regarding items of footwear provided with devices suitable for ventilating the inside of the item of footwear and extracting the air, and hence the moisture, from the item of footwear itself, but they all present the drawback of not envisaging extraction of the condensate, and hence, in the event of excessive perspiration, the ventilation can prove ineffective.

The Korean patent No. KR 20040037042 describes an item of footwear provided with a device suitable for extracting the air from the item of footwear itself, constituted by a pump operated by the foot during walking, joined to a valve that enables flow in just one direction.

The patent No. WO 2007/032037 A1 describes a system of aeration of a gap made in the upper, actuated by a pump, which is in turn operated by the foot. Said patents seek to prevent condensation of the humidity by means of an adequate ventilation. However, they do not envisage devices suitable for extracting the water that in any case condensates when the conditions are particularly difficult, as in the case of high ambient temperatures, which favour perspiration. In such cases, the attempt is in any case, via ventilation, to bring about re-evaporation of the water so that it can be expelled in the gas phase. Obviously, in the case where the conditions that have caused condensation of the humidity persist, re-evaporation does not occur and, hence, the person will remain for a long time with his feet damp.

The present invention provides a remedy for the drawback described by proposing an air-conditioned item of footwear of the type that envisages first means, operated by the foot, designed to generate a circulation of air, taken in from outside, in a gap made in the upper of the item of footwear and is characterized in that it envisages second means designed to expel outside the item of footwear the water deriving from condensation of the water vapour emitted by the foot, said condensation occurring within the gap of the upper as a result of cooling provided by said air.

According to a preferred embodiment, there is provided a chamber for collection of the water deriving from condensation of the water vapour emitted by the foot, said collection chamber being set between the sole and an internal lining of said item of footwear and being in communication with the gap of the upper, where condensation of the water vapour occurs.

As will emerge clearly from the ensuing description, the structure of the item of footwear according to the invention is such that the water that condensates does not dampen the foot, but is conveyed towards said collection chamber, from which it is taken in to be expelled outside the item of footwear itself.

A first advantage deriving from the use of items of footwear according to the invention is a consequence of the fact that the humidity condensates and collects in a purposely provided site, i.e., said collection chamber. In fact, the aim is not to prevent condensation, as in the case of prior techniques, which become critical when the environmental conditions are particularly severe. According to the present invention, condensation is favoured so as to enable immediate removal of the water from the foot in order to prevent the latter from getting wet, said water being then promptly expelled from the item of footwear.

The invention will now be described, purely by way of non-limiting illustration, according to a preferred embodiment, with reference to the annexed figures, in which:

FIG. 1 shows in three orthogonal views the item of footwear according to the invention; and

FIGS. 2, 3 and 4 show sections of the item of footwear according to three orthogonal planes.

With reference to FIG. 1, designated by the reference number (1) is an item of footwear according to the invention. In the case provided in the example, a waterproof boot is shown, which hence enables use on wet floors, even where the water is several centimetres deep.

Illustrated in FIGS. 2, 3 and 4 are sections of said boot (1) obtained with three orthogonal planes, as indicated in FIG. 1.

In particular, illustrated in FIG. 2 is the inside of the sole (2) of the boot (1), in which there appear two elastic bladders, or pumps, (3) and (4), whereas illustrated in FIGS. 3 and 4 is the upper (5) viewed from inside. The bladders (3) and (4) are housed in a recess, which forms a chamber (2 a), which can be seen more clearly in the subsequent FIGS. 3 and 4, and is made in the sole (2), and are connected, in the way that will be specified in what follows, with tubes (3 a, 3 b, 4 a, 4 b).

The upper (5) is constituted by an external impermeable membrane (5 a) and by an internal transpirant membrane (5 b), for example of the type known under the commercial name of gore-tex™, which is characterized in that it enables passage of water in the vapour state, but not in the liquid state. The two membranes (5 a) and (5 b) are separated from one another by a structure such as to identify a gap (6), preferably obtained by means of channels, the function of which will be illustrated in what follows. The gap (6) is open in the top part in such a way as to be in communication with the external air.

Set in the bottom internal part of the item of footwear (1), immediately above the sole (2), is a lining (7), which has a structure substantially the same as that of the upper (5), i.e., with an external impermeable membrane (7 a), which is preferably ribbed, and a transpirant internal membrane (7 b). Also in this case the two membranes (7 a) and (7 b) are separated from one another by a structure such as to identify a gap (8), preferably obtained by means of channels, which connect up with the channels made in the gap (6) of the upper (5), the function of which will be illustrated in what follows. Furthermore, the external membranes (5 a, 7 a) are connected to one another in a continuous way, as are the internal membranes (5 b, 7 b). Basically, the upper (5) and the lining (7) form a shell that envelops the foot completely, the transpirant membrane (5 b, 7 b) being inside, in contact with the foot itself, and the impermeable membrane (5 a, 7 a) being on the outside.

Given the nature of the membranes, the water in which the boot were to be immersed cannot come into contact with the foot, being stopped by the impermeable membranes (5 a, 7 a), as well as by the sole (2), whilst the moisture due to the perspiration of the foot traverses the transpirant membranes (5 b, 7 b) and reaches the gap (6, 8) of said shell.

Made in the front part and in the rear part of said shell are two apertures (9) and (10), preferably controlled by a leaf valve (9 a) and (10 a), respectively, which set the gap (6, 8) in communication with the chamber (2 a). The function of the valves (9 a) and (10 a) will be described in what follows.

The elastic bladder (3) is connected, by means of non-return valves (3 c) and (3 d) appropriately oriented so as to enable flow just towards the front part of the item of footwear (1), to said two tubes (3 a) and (3 b), respectively. The tube (3 a) is directed towards the front part of the item of footwear (1) and is inserted in the gap (6) of the upper (5), whilst the tube (3 b) is directed towards the rear part of the item of footwear (1) and is also inserted in the gap (6) of the upper (5).

In the same way, the elastic bladder (4) is connected, by means of non-return valves (4 c) and (4 d) appropriately oriented so as to enable flow just towards the rear part of the item of footwear (1), to two tubes (4 a) and (4 b), respectively. The tube (4 a) is directed towards the front part of the item of footwear (1) and terminates just in front of the bladder (4), whilst the tube (4 b) is directed towards the rear part of the item of footwear (1) and is connected with the outside through the rear edge of the sole (2).

The two elastic bladders (3) and (4), being set in the chamber (2 a), between the sole (2) and the internal lining (7), are squeezed by the weight of the person, when the person stops in an upright position, but return elastically into the position of rest, indicated in the figures, when the person, walking, raises his foot.

In the example of embodiment described, the two bladders (3) and (4) are set in a position corresponding to the sole of the foot, i.e., between the internal lining (7) and the sole (2) of the item of footwear (1). Alternatively, they can be housed also in a position corresponding to the heel, i.e., between the internal lining (7) and the heel of the item of footwear (1), in so far as, also in this position, they are subject to alternate squeezing and release.

The alternation of squeezing and release of the elastic bladders (3) and (4), together with the presence of the non-return valves (3 c, 3 d) and (4 c, 4 d), respectively, appropriately oriented, determines a flow towards the front part of the item of footwear (1) in the tubes (3 a, 3 b) and towards the rear part of the item of footwear (1), in the tubes (4 a, 4 b), respectively.

The flow generated by the elastic bladder (3) causes a circulation of air within both the gap (6) of the upper (5) and the gap (8) of the bottom (7), recalling air from the rear part of the upper (5), according to the path indicated by the arrows in FIG. 3.

The arrangement of the tubes (3 a) and (3 b) with the ends within the gap (6) of the upper (5) causes the main flow of air to be inside the upper (5). However, given the contiguity between the upper (5) and the bottom (7), there arises an appreciable flow of air also within the bottom (7).

When perspiration of the foot starts, the humidity emitted by the foot itself passes to the vapour state through the transpirant membranes (5 b) and (7 b) and collects in the gaps (6) and (8).

The flow of air in the gap (6) and (8), of the upper (5) and of the bottom (7) respectively, caused by the repeated squeezing and release of the bladder (3), cools the vapour that has penetrated into the gap (6, 8) and condenses it. The water thus obtained drips along the channels existing in the gap (6, 8) and, through the apertures (9) and (10), enters the chamber (2 a), and collects on the bottom thereof, said gap (6, 8) being pervious to the condensate.

The repeated squeezing and release of the bladder (4) in turn causes suction of the condensate, which is then expelled from the rear part of the item of footwear (1) after passing through the tube (4 a), the bladder (4) itself and the tube (4 b), said flow being in just one direction thanks to the non-return valves (4 c) and (4 d).

The function of the valves (9 a) and (10 a) is to prevent the condensate within the gap (6, 8) of the shell formed by the upper (5) and by the bottom (7) that has dripped in the collection chamber (2 a) from returning into the gap (6, 8) itself, thus favouring suction by the pump (4) and expulsion of the water itself outside the item of footwear (1). Closing of the valves (9 a) and (10 a) can occur, for example, as a result of the water that exerts pressure from beneath on the leaves of said leaf valves (9 a) and (10 a) and keeps them closed.

As emerges clearly from the foregoing description, the item of footwear according to the invention manages to keep the foot drier because it causes condensation of the humidity, without dampening the foot thanks to the transpirant membrane, i.e., the membrane that is permeable to vapour but not to the water, and the expulsion of the condensate.

The invention has been described purely by way of non-limiting illustration according to a preferred embodiment. The person skilled in the sector may find numerous other embodiments, all of which fall within the sphere of protection of the ensuing claims. 

1. An air-conditioned item of footwear (1) of the type that envisages first means, operated by the foot, designed to generate a circulation of air in a gap (6) made in the upper (5) of said item of footwear, said air being taken in from outside said item of footwear (1), said item of footwear being characterized in that it envisages second means designed to expel outside said item of footwear the water deriving from condensation of the water vapour emitted by the foot, said condensation occurring within said gap (6) of said upper (5) as a result of cooling actuated by said air.
 2. The air-conditioned item of footwear according to claim 1, characterized in that it envisages a collection chamber (2 a) for said water deriving from condensation of the water vapour emitted by the foot, said collection chamber (2 a) being set between the sole (2) and an internal lining (7) of said item of footwear (1), said collection chamber (2 a) being in communication with said gap (6) of the upper (5) so that the condensate, dripping within the gap (6) of the upper (5), collects in said collection chamber (2 a).
 3. The air-conditioned item of footwear according to claim 1, characterized in that said upper (5) comprises an external membrane (5 a) and an internal membrane (5 b), which is permeable to vapour and impermeable to water, said external membrane (5 a) and internal membrane (5 b) being set at a distance from one another so as to identify a gap (6), pervious to the condensate.
 4. The air-conditioned item of footwear according to claim 3, characterized in that said external membrane (5 a) of the upper (5) is impermeable.
 5. The air-conditioned item of footwear according to claim 1, characterized in that it envisages a lining (7) comprising an internal impermeable membrane (7 a) and an external membrane (7 b) permeable to vapour and impermeable to water, said internal membrane (7 a) and external membrane (7 b) being set at a distance from one another so as to identify a gap (8) pervious to the condensate.
 6. The air-conditioned item of footwear according to claim 1, characterized in that said upper (5) is connected with said internal lining (7), said upper (5) and said lining (7) constituting a shell that envelops the foot completely, the transpirant membrane (5 b, 7 b) being inside, in contact with the foot, and the impermeable membrane (5 a, 7 a) being on the outside, there being provided at least one orifice (9, 10) designed to set in communication the gap (6, 8) of said shell with said collection chamber (2 a).
 7. The air-conditioned item of footwear according to claim 6, characterized in that it envisages valves (9 a) and (10 a), which are applied to said orifices (9) and (10), respectively, and are designed to prevent return, in the gap (6, 8) of the upper (5) and of the bottom (7), of the condensate that has flowed in the collection chamber (2 a).
 8. The air-conditioned item of footwear according to claim 1, characterized in that said first means designed to generate a circulation of air in said gap (6) made in the upper (5) of said item of footwear (1), comprise an elastic bladder (3) connected to tubes (3 a) and (3 b) that are inserted within said gap (6) of said upper (5), said tubes (3 a) and (3 b) being connected to said elastic bladder (3) by means of non-return valves (3 c) and (3 d) oriented so as to enable flow in just one direction, so that alternate squeezing and release of said bladder (3) causes a flow of air coming from outside said item of footwear (1) that traverses said gap (6).
 9. The air-conditioned item of footwear according to claim 1, characterized in that second means designed to expel outside said item of footwear (1) the water deriving from condensation of the water vapour emitted by the foot comprise an elastic bladder (4) connected to tubes (4 a) and (4 b), connected to said elastic bladder (4) by means of non-return valves (4 c) and (4 d) oriented so as to enable flow in just one direction, said tube (4 a) being in communication with said collection chamber (2 a) and said tube (4 b) being in communication with the outside of said item of footwear (1) so that alternate squeezing and release of said bladder (4) causes suction of the water from said collection chamber (2 a), through said tube (4 a), and expulsion of said water outside the item of footwear (1) through said tube (4 b).
 10. The air-conditioned item of footwear according to claim 8, characterized in that said bladders (3) and (4) are set in a position corresponding to the soles of the foot, between the internal lining (7) and the sole (2) of said item of footwear (1).
 11. The air-conditioned item of footwear according to claim 8, characterized in that said bladders (3) and (4) are set in a position corresponding to the heel, between the internal lining (7) and the heel of said item of footwear (1). 